Incandescent lamp.



UNITED STATES i Patented June 2, 1903.

PATENT OFFICE.

WILLIAM R. BURROVVS, OF NEWARK, NEW JERSEY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INCANDESCENT'LIVIP.

SPECIFICATION forming part of `Letters ratentno. 729,730, dated .Tune 2, 1903.

To all whom it may concern.-

Beit known that I, WILLIAM R. BURRows, a citizen of the United States, residing at Newark, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Incandescent Lamps, (Case No. 1,944,) of which the following is a specification. i This invention relates to incandescent lamps. I i

The object is to prevent damage to the joint between the platinum leads and `the pillar which supports the filament.

In incandescent lamps `employed in series lighting, which carry relatively heavy currents, much damage is occasioned to the lamp, and, in fact, the'seal is frequently destroyed from the heating of the leading-in wires to a comparatively high temperature, which under repeated heating and cooling creates a defective joint at the glass seal and ultimately destroys the vacuum. i

It is the object of my invention to prevent this defect. I proceed by mounting on the leading-in wires, inside'of the bulb and above" the glass pillar or stem which supports the filament, radiating devices which act to disperse the heat at the point at which they are attached to the wires, and thus prevent it being communicated to the glass stem. I prefer to form these radiators of globules of glass, which are fused fast to the platinum leading-in wires, and thus form a good tight joint which lasts throughout the life of the lamp.

My invention therefore comprises au incan. descent lamp having radiators mounted upon the leading-in wires` above the glass seal to prevent the communication of heat to said seal and the resulting damage.

-It comprises other narrower features the novelty of which will be specifically pointed out hereinafterand will be definitely indicated in the appended claims.

In the accompanying drawing, which illustrates my invention, is shown a side elevation of a series incandescent lamp embodying my improvements. j

l represents the base ofthe lamp, which is made of a brass cup adapted to be inserted `platinum leading-in wires 3 3a.

sentira/15,319. (No moda.)

in a suitable socket provided in the series' circuit in which the lamp is to be used.

2 represents the glass stem, the lower part of which is provided with a hermetic joint by a4 fused connection with the neck of the bulb and into the other end of which are fused the In series lamps as ordinarily constructed, in which the filaments are quite thick, and therefore reL quire a heavy current to bring them to incandescence, these platinum wires become very hot and under repeated heating and cooling produce a defective joint with the glass stem, permitting air to leak into the bulb and impairing the vacuum. In order to avoid this, I mount on the wires glass beads, as in dicated at 4 Ll, placing one of these beads on each wire, so as to provide a large radiatingsurface for heat. I find that this effectually prevents the impairment of the joint with the stem by cutting olf the transfer of heat to the lower part of the leading-in wire and keeping it comparatively cool. These glass beads are mounted on the leading-in wires before the filament is cemented to the terminals.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

l. Means for preserving the seal of an incandescent electric lamp, comprising heat-radiators, of large superficial area compared to the leading-in wires, surrounding each wire at a point below the filament-joint and near the seal.

2. Means for preserving the seal of an incandescent lamp, comprising glass radiators of large superficial area compared to the leading-in wires, one on each wire below the {ilament-joint and near the seal.

3. Means for preserving the sealof an incandescent electric lamp, comprising glass radiators of large superficial area compared to the leading-in wires, one fused to each wire below the filament-joint and near the seal.

In witness whereof Ihave1 hereunto set my hand this 28th day of January, 1901.

WILLIAM R. BURROWS.

Witnesses:

DANIEL HAND, J. W. HOWELL. 

